As is well known, a variety or products typically marketed by fast-food retail establishments are provided to consumers after having been prepared with condiments such as ketchup, mustard, mayonnaise, relish and Thousand Island dressing. In this regard, many such establishments currently utilize manual dispensing systems for such condiments which deliver a metered quantity of the condiment therefrom.
The majority of prior art condiment-dispensing systems generally comprise portable, hand-held, manually-activated dispensing devices which are used to supply a quantity of the condiment to a food product. Although such prior art dispensing systems have generally proven suitable for their intended purposes, they possess inherent deficiencies which have detracted from their overall effectiveness and use in the trade.
The foremost of these deficiencies has been the inability of the prior art dispensing devices to dispense more than one variety of condiment, in that such devices are typically suited for dispensing only one condiment at a time. Moreover, the dispensing devices currently known are generally hand-held, mechanical devices, having a storage hopper for the condiment. Due to the relatively small size of the hopper needed to permit proper handling and manipulation of the device by the user, such devices must be refilled frequently with the condiment. This need for frequent refilling decreases the operational effectiveness of the device and gives rise to a greater likelihood of condiment contamination since the device is more susceptible to having a foreign material introduced thereinto during a refilling operation.
Thus, there has existed a substantial need in the art for a reliable, relatively inexpensive apparatus for dispensing a variety of condiments through a Single dispensing unit in a metered quantity and at a low flow rate, which is adapted to be connected directly to corresponding modern, sanitary bag-in-box containers for such condiments, thereby eliminating the need for frequent refillings of the dispensing system and reducing the possibility of condiment contamination. In recognition of this need, the device disclosed in Application Ser. No. 08/012,940 of which the present application is a continuation-in-part was developed by the Applicant.
The condiment dispensing system disclosed in Ser. No. 08/012,940 comprises a fluid driven pump having a piston which is operable to draw a quantity of condiment from a condiment reservoir into an interior cavity of the pump via an inlet check valve when it moves through an intake stroke, and dispense the quantity of condiment from the interior cavity to a dispensing apparatus via an outlet check valve when it moves through an exhaust stroke. Threadably engaged to the piston is a wiper member having a peripheral edge disposed in abutting, sealed contact with the inner surface of the interior cavity. The wiper member moves concurrently with the piston and is operable to wipe the inner surface of the interior cavity during the intake and exhaust strokes of the piston so as to prevent any condiment from passing between the inner surface of the interior cavity and the piston to a location intermediate the piston and an end of the pump housing. The inclusion of the wiper member prevents the binding of the pump piston and the clogging of the inlet and outlet check valves by preventing the chunks or particles of highly viscous condiments such as relish from being captured between the piston and the inner surface of the interior cavity of the pump housing. The dispensing apparatus of the system includes a plurality of valve stems which are oriented relative a plurality of fluid passages in a manner operable to provide pressurized fluid to the pump to initiate an exhaust stroke of the piston when in a first position, and allow the pressurized fluid to be vented from the pump to initiate an intake stroke of the piston when in the second position. The valve stems are adapted to regulate the flow of pressurized fluid to the pump depending on the type of condiment being dispensed therefrom. In this respect, the flow rate of pressurized fluid to the pump may be selectively adjusted so that less viscous condiments such as mustard and ketchup will be prevented from being dispensed too rapidly from the pump in a manner causing such condiments to be splattered and sprayed from the dispensing apparatus rather than being evenly and smoothly dispensed.
Though this condiment dispensing system addresses many of the deficiencies of the prior art condiment dispensing systems, this system itself has certain deficiencies which detracts from its overall utility. In this respect, it has been found that immediately subsequent to the dispensation of a quantity of condiment from the dispensing apparatus as occurs during ah exhaust stroke of the piston, residual condiment from the dispensing apparatus frequently drips therefrom onto counters and/or floors, thus necessitating frequent clean-up of the food preparation area. The drippage problem is particularly evident when the dispensing apparatus is used to pump less viscous condiments such as ketchup and mustard, as opposed to condiments of increased viscosity such as relish or Thousand Island dressing. As such, there exists a need in the art for a condiment dispensing system having the characteristics of the system disclosed in Ser. No. 08/012,940, but which is further adapted to pull a vacuum within the product outlet of the pump during the intake stroke of the piston to eliminate drippage of the residual condiment from the condiment dispensing apparatus. The present invention addresses these and other deficiencies associated with the prior art condiment dispensing systems.